I have a 1996 Ranger, 4wd, 4.0, supercab. I think it's overheating. The dash gauge is hitting the HOT mark quickly whether at idle or at speed. This is a new occurance. I have had this truck for 7 years and this is a first. When I got home and I was reading hot the first time the upper coolant hose was flat (like the internal vacuum pulled it in) and had white spots on it, so I assume it had a coolant leak. Since then I have replaced the upper coolant hose and drained and flushed the coolant and refilled with 50/50. I have ran it several times after replacing the coolant it heats all the way from the Cold mark to the Hot mark in 10-15 minutes or so. I have found no leaking coolant anywhere. I have checked the upper coolant hose after the engine get up to temp and it does get hot so I assume the pump is sending coolant. The rad is not clogged up with bugs or leaves or anything. The fan kicks on and seems to pull quite a bit of air. The shroud around the fan is fine. What is the next thing to check???? Could the gauge all-of-a-sudden go bad?? If I should try the dash temp guage sending unit, any help or walkthru would be appreciated on that or any other recommendation.

Thanks in advance for any replies and for the great forum.

 

How about the thermostat? Also, since your upper hose was flat that would lend me to believe that maybe your radiator cap isn't allowing the coolant to be pulled back in from the overflow recovery tank. You haven't by chance changed the lower hose and forgot to put the spring back inside the hose did you? Don't know what all you have done to the cooling system but am just throwing out some ideas.

John

 

How would I test the thermostat?

I have had the overflow tank filled and after running it the first time after refilling it was empty. I have refilled and now it still has coolant in it.

I have not touched the lower coolant hose I got down and looked at to see if I could see any soft areas or holes or anything. But since I didn't see anything so I didn't touch it. I did not even detach it.

I am willing to try anything....just give me some ideas.